Adjustable cam



Jan. 31, 1967' Y P. H. WECHSLER 3,301,089

ADJUSTABLE CAM Filed Nov. 9, 1964 1 /701; JEA/Qy TVEGMSLJEQ v INVENTOR.

United States Patent 3,301,039 ADJUSTABLE CAM Paul Henry Wechsler, 603 Moltke Ave., Scranton, Pa. 18505 Filed Nov. 9, 1964, Ser. No. 409,794 7 Claims. (Cl. 74-568) The present invention relates to an adjustable cam, and more particularly to an adjustable cam in which a ring of flexible material on a rotatable drum has some parts of the ring in one plane along the drum axis and other parts of the ring in another plane along the drum axis, and is held by movable positioner elements.

Cams have heretofore been provided which could be adjusted so that the movement of the cam follower could be varied. In general, however, the prior art adjustable cams were expensive to manufacture, often requiring complex machining or forming operations. Further, the adjustable cams heretofore known generally used screws in order to adjust the cams. The use of screws required threading of holes in the cam assembly, or the provision of nuts to cooperate with the screws, and for either construction additional expense was entailed, or the number of parts required was unduly mutiplied. Further, the constructions utilizing screws were inherently time-consuming in making an adjustment of the cam, and the adjustment was often difficult to make. The prior cams were also subject to inadvertent movement of the adjusting mechanism.

An object of the present invention is to provide a cam which may be readily adjusted.

Another object of the present invention is the provision of an adjustable cam of simple and economic construction.

A further object of the present invention is to provide an adjustable cam capable of providing multiple cam actions during a single cycle.

Another object of the present invention is the provision of an adjustable cam which does not require screws.

Yet another object of the present invention is to provide an adjustable cam which will remain fixed in any selected position.

Still another object of the present invention is the provision of an adjustable cam construction which may be readily ganged.

The novel featureswhich are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages thereof will be better understood from the following description considered in connection with the accompanying drawing in which a presently preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawing is for the purpose of illustration and description only, and is not intended as definition of the limits of the invention.

FIGURE 1 is a perspective view of an assembly of multiple cams in accordance with the present invention;

FIGURE 2 is a perspective view of a single adjustable cam in accordance with the present invention, and showing a cam follower;

FIGURE 3 is a cross-sectional view taken on the line 3-3 of FIGURE 2;

FIGURE 4 is a cross-sectional view taken on the line 4-4 of FIGURE 3;

FIGURE 5 is an exploded perspective view showing a portion of the cam surface and a positioner element.

Referring now to the drawings, wherein like or corresponding reference numerals are used to designate like or corresponding parts throughout the several views, there is shown in FIGURE 1 a ganged or multiple ca-m assembly generally designated and including a mounting plate 3,301,089 Patented Jan. 31, 1967 ice 11, a drive shaft 12 journaled therein, a gear 13 on shaft 12, and a gear 14 in mesh with gear 13. Gear 14 is fixed to a cam shaft 16 which is also journaled in the mounting plate 11, and which carries a plurality of adjustable earns 20' A cam follower 21 is provided for cooperating with each adjustable cam 20, and controls the operation of a device such as a switch 22.

Follower 21 is in the form of a lever arm, and carries a roller 21a for engagement with a ring 40.

Referring now to FIGURE 2, the adjustable cam 20 on the cam shaft 16 may be seen to comprise a drum '23 having a groove 24 in the surface thereof, groove 24 lying in a plane perpendicular to the axis of drum 23. Grooves 25 and 26 are also provided in the surface of drum 23, adjacent to and parallel with groove 24, on either side thereof.

Positioner elements generally designated 30 are carried by the drum, in a manner set forth below, and a resilient ring 40 is positioned on the drum, lying partly in the groove 25 and partly in the groove 26. The ring 40 crosses the groove 24, and is held by the positioner elements 30 at the point of crossing of groove 24; ring 40 is of flexible material, preferably resilient, and is conveniently made of a rubber-like material of circular cross-section.

As may be seen from FIGURES 4 and 5, the groove 24 is generally rectangular in cross-section and is relatively deep, whereas the grooves 25 and 26 on either side thereof are generally sector-shaped in cross-section and are relatively shallow.

The positioner element 30 is provided with a circumferentially extending projection 31 (see also FIGURE 3) which is of rectangular cross-section and which mates with the groove 24, as is best shown in FIGURE 4. Element 30 is provided with a pair of circumferentially spaced lugs 32 and 33 which extend outwardly of the surface of drum 23. A groove 34 of sector-shaped cross-section extends between the lugs 32 and 33, and is generally parallel to the axis of drum 23. Lug 32 has a ramp 36 thereof, which extends from the surface of drum 23, and lug 33 has a handle 37 which extends outwardly.

The cam 20 is assembled by placing the ring 40 aboutthe drum 23, and by placing two or more of the positioner elements 30 on the drum 23, with the projections 31 in the groove 24. The ring 40 is then placed so that it is partly in groove 25 and partly in groove 26, positioner elements 30 being utilized to provide a guiding and supporting structure for carrying the ring 40 between groove 25 and groove 26, across groove 24. Thus, ring 40 is in mating relationship with grooves 25, 26 and 34. The drum 23, with additional drums 23 as desired, are secured to the shaft 16 with the groove 26 in the same plane as the follower 21. When the shaft 16 and drum 23 are rotated, the follower will ride in an outer or raised position on ring 40, where ring 40 is in groove 26, and will then descend, by means of ramp 36 of a first positioner element 30 to the level of the surface of drum 23, which is an inner or lower position, as will be understood from FIG- URES 2 and 3. As drum 23 continues to rotate, the roller 21a will engage the ramp 36 of the lower positioner element 30 shown therein and will rise to the level of the outer surface of ring 40. Thus, the switch 22, or upper device, will be actuated from a first position, to a second position, and then back to the first position.

To adjust the actuating position for the cam follower 21, it is only necessary to lift the positioner element from groove 24, rotate it so as to tend to straighten that portion of ring 40 carried in the groove 34, reposition the positioner element 30 with the aid of handle 37, and reinsert its projection 31 into groove 24 at the new desired position.

There has thus been provided an adjustable cam made up of simple and economical parts, and which may be readily adjusted to change the actuating position for the cam follower. The adjustable cam herein disclosed does not require screws, and due to the resiliency of the ring 40, is readily retained in any selected position. While only two positioner elements have been disclosed in the drawings, it will be understood that more than two may be utilized on a single drum, to thereby provide for multiple cam actions during a single drum rotation. As will be apparent, as many of the adjustable cams of the present invention as desired may be gauged on a single shaft.

The invention is to be construed not only in the light of the drawings and specification hereof, but as provided in the claims appended hereto.

What is claimed is:

1. An adjustable cam comprising:

a drum, said drum having a first circumferential groove in the peripheral surface thereof in a plane perpendicular to the drum axis, second and third circumferential grooves parallel to said first groove;

positioner elements slidably adjustably mounted in said first groove, each of said positioner elements having a circumferentially extending projection in the said first groove in mating relationship therewith and a pair of circumferentially spaced lugs extending outwardly of the surface of said drum;

a flexible ring encircling said drum and lying partly in said second groove and partly in said third groove, said ring engaging said lugs of said positioner elements and being guided thereby to said second and third grooves, the outermost part of said ring being outwardly of the drum surface; and a cam follower contiguous with said drum and overlying said third groove for movement by the outermost part of that portion of said ring in said third groove.

2. The cam of claim 1, said ring being of resilient material.

3. An adjustable cam comprising:

a drum, said drum having a first circumferential groove in the peripheral surface thereof in a plane perpendicular to the drum axis, second and third circumferential grooves of section-shaped cross-section parallel to and adjacent said first groove on either side thereof;

positioner elements slidably adjustably mounted in said first groove, each of said positioner elements having a circumferentially extending projection in said first groove in mating relationship therewith and a pair of circumferentially spaced lugs extending outwardly of the surface of said drum, at least one of said lugs having a ramp extending from the surface of said drum;

a flexible resilient ring of circular'cross-section encircling said drum and lying partly in said second groove and partly in said third groove in mating relationship therewith, said ring extending across said first groove between the lugs of said positioner elements, the outermost part of said ring being outwardly of the drum surface; and, a cam follower contiguous with said drum and overlying said third groove for movement by the outermost part of that portion of said ring in said third groove.

4. An adjustable cam comprising:

a drum, said drum having a first circumferential groove in the peripheral surface thereof in a plane perpendicular to the drum axis, said first groove being relatively deep, second and third relatively shallow circumferential grooves parallel to and adjacent said first groove on either side thereof;

positioner elements slidably adjustably mounted in said first groove, each of said positioner elements having a circumferentially extending projection in said first groove in mating relationship therewith, and' a pair of circumferentially spaced lugs extending outwardly of the surface of said drum, at least one of said lugs having a ramp extending from the surface of said drum and partially overlying said third groove;

a resilient ring encircling said drum and lying partly in said second groove and partly in said third groove, said ring extending across said first groove between the lugs of said positioner elements, the outermost part of said ring being outwardly of the drum surface; and a cam follower contiguous with said drum and overlying said third groove for movement by said ramp and the outermost part of that portion of said ring in said third groove.

5. An adjustable cam comprising:

a drum, said drum having a first circumferential groove in the peripheral surface thereof in a plane perpendicular to the drum axis, said first groove being relatively deep, second and third relatively shallow circumferential grooves of sector-shaped cross-section parallel to and adjacent said first groove on either side thereof positioner elements slidably adjustably mounted in said first groove, each of said positioner elements having a circumferentially extending project-ion in said first groove in mating relationship therewith and a pair of circumferentially spaced lugs extending outwardly of the surface of said drum, at least one of said lugs having a ramp extending from the surface of said drum and partially overlying said third groove;

a resilient ring encircling said drum and lying partly in said second groove and partly in said third groove, said ring extending across said first groove between the lugs of said positioner elements, the outermost part of said ring being outwardly of the drum surface, said ring being of circular cross-section mating with the grooves in which it lies; and a cam follower contiguous with said drum and overlying said third groove for movement by said ramp and the outermost part of that portion of said ring in said third groove.

6. An adjustable oam comprising:

a drum, said drum having a first circumferential groove of rectangular cross-section in the peripheral surface thereof in a plane perpendicular to the drum axis, said first groove being relatively deep, second and third relatively shallow circumferential grooves of sector-shaped cross-section parallel to and adjacent said first groove on either side thereof;

positioner elements slidably adjustably mounted in said first groove, each of said positioner elements having a circumferentially extending projection of rectangular cross-section in mating engagement with said first groove and a pair of circumferentially spaced lugs extending outwardly of the surface of said drum, at least one of said lugs having a ramp extending from the surface of said drum and partially overlying said third groove;

a resilient ring encircling said drum and lying partly in said second groove and part-1y in said third groove, said ring extending across said first groove between the lugs of said positioner elements, the outermost part of said ring being outwardly of the drum surface, said ring being of circular cross-section mating with the grooves in which it lies; and a cam follower contiguous with said drum and overlying said third groove for movement by said ramp and the outermost part of that portion of said ring in said third groove.

7. An adjustable cam comprising:

a drum, said drum having a first circumferential groove of rectangular cross-section in the peripheral surface thereof in a plane perpendicular to the drum axis, said first groove being relatively deep, second and third relatively shallow circumferential grooves of sector-shaped cross-section parallel to and adjacent said first groove on either side thereof;

positioner elements slidably adj ustably mounted in said first groove, each of said positioner elements having a circumferentially extending projection of rectangular cross-section in mating engagement with said first groove and a pair of cincumferentially spaced lugs extending outwardly of the surface of said drum,

(E which it lies; and a cam follower contiguous with said drum and over-lying said third groove for movement by said ramp and the outermost part of that portion of said ring in said third groove,

References Cited by the Examiner a groove between said lugs generally parallel to the drum axis, at least one of said lugs having a ramp extending from the surface of said drum and partial- UNITED STATES PATENTS 1,856,832 5/1932 Halvorson 74568 1y overlying said third groove, at least one of 10 10/1952 Ueltschl 74 568X said lugs having an outwardly projecting handle; FOREIGN PATENTS a resilient ring encircling said drum and lying partly 859 600 1/1961 Great Britain in said second groove and partly in said third groove,

Said ring extending across said first groove FRED c. MATTERN, JR., Primary Examiner. in the groove between the lugs of said position- 15 er elements, the outermost part of said ring being MILTON KAUFMAN Examiner outwardly of the drum surface, said ring being of W. S. RATLIFF, Assistant Examiner. circular cross-section mating with the grooves in 

1. AN ADJUSTABLE CAM COMPRISING: A DRUM, SAID DRUM HAVING A FIRST CIRCUMFERENTIAL GROOVE IN THE PERIPHERAL SURFACE THEREOF IN A PLANE PERPENDICULAR TO THE DRUM AXIS, SECOND AND THIRD CIRCUMFERENTIAL GROOVES PARALLEL TO SAID FIRST GROOVE; POSITIONER ELEMENTS SLIDABLY ADJUSTABLY MOUNTED IN SAID FIRST GROOVE, EACH OF SAID POSITIONER ELEMENTS HAVING A CIRCUMFERENTIALLY EXTENDING PROJECTION IN THE SAID FIRST GROOVE IN MATING RELATIONSHIP THEREWITH AND A PAIR OF CIRCUMFERENTIALLY SPACED LUGS EXTENDING OUTWARDLY OF THE SURFACE OF SAID DRUM; A FLEXIBLE RING ENCIRCLING SAID DRUM AND LYING PARTLY IN SAID SECOND GROOVE AND PARTLY IN SAID THIRD GROOVE, SAID RING ENGAGING SAID LUGS OF SAID POSITIONER ELEMENTS AND BEING GUIDED THEREBY TO SAID SECOND AND THIRD GROOVES, THE OUTERMOST PART OF SAID RING BEING OUTWARDLY OF THE DRUM SURFACE; AND A CAM FOLLOWER CONTIGUOUS WITH SAID DRUM AND OVERLYING SAID THIRD GROOVE FOR MOVEMENT BY THE OUTERMOST PART OF THAT PORTION OF SAID RING IN SAID THIRD GROOVE. 